Method and machine for manufacturing paper



Y June 22 f, 1926.

E. J. WILSON Er Al.

METHOD AND MACHINE FOR MANUFACTURING PAPER Filed .June 19, 1925 PatentedJune 22, 1926.

UNITED STATES l 1,589,450 PATENT OFFICE.

EZEKIEL J. WILSON, OF EAST GREENBUSH, AND EDWIN L BEES, 0F ALBANY,-NEW

YORK, ASSIGNORS '10 F. C. H'UYCK & SONS, OF BENSSELAEB, NEW VYORK., AOOR- PORATION OF NEW YORK.

METHOD AND MACHINE FOIQYMANUFACTURING PAPER.

Application led June 19, 1925. Serial'No. 38,368.

The present invention relates to the manufacture of paper, thisapplication being a continuation in part of the application ofWilson'and Rees, Serial No. 595,541, filed Octoberh19, 1922.

In the-manufacture of paper on a paper lmaking machine a continuoustravelling web of paper stock is formed on the Fourdrinier wire, orotherwise, and passes between .a pair of couch rolls to a series ofvpresses which act to express a portion of thev surplus water therefrom,after* whichthe web is subjected to the drying action of a seriesofheated calender rolls which finally dry and iinish the web. For themost efficient operation, the web of paper stock, as it comes froml thecouch rolls, not only should contain av certain percentage'of moisture,but also should have certain percentages of this moisture removedtherefrom during each successive pressingr operation, so that as littleas possible of the moisture will remain'tovbe removed by the heatedcylinders of the dryers, and yet Without such operation of the pressesas to crush the stock or deleteriously aiect the -fibres. The mechanismswhich operate successively upon the web yof paper stock during itspassage through the machine should therefore, for the most efficientoperation, be adjusted and regulated" to maintain substantially uni-4form percentages of moisture in the web of stock at the points in itstravel between the successive loperations thereon, and to effect maximumpermissible diminutions in moisture content` of the web in its passagethrough successive operations. They should also be so adjusted andregulated that at every point in its travel the moisture will not varygreatly throughout the Width of the We The present invention providesfor the regulation of the operations to which the web of paper stockis'successively subjected to maintain the proper progressive decrease inmoisture in the stock between successive operations and this isaccomplished by indi-l eating or indicating and recordingthe moistureand variations in the moisture in the stock at points in its travel andregulating the mechanisms for operating on the web in accordance withsuch indications or records. The moisture and variations in the moisturein the web' of stock traveling through the machine are preferablymeasured or indicated by passing a current. of electricityl through theweb from one side tothe other and indicating the resistance offered bythe web tothe passage of the current, since it has been found that theconductivity of thisr thin layer of damp paper stock varies withvariations in the molsture therein, and since it has also been foundthat even after a la ge part of the moisture has been removed,t 1s thinlayer of stock does not offer suicient resistance to the passage of anelectric current to preclude the use of currents of measurableintensity.

Ac ording to a feature of the present invention, the indicating meansincludes a novel type of electrode or contact member,

which is adapted to have a smooth, unvary ing engagement of large areawith the web and serves to permit an accurate indication of theelectrical resistance of the web without being thrown off or otherwiseinfiuenced by any irregularities in the stock. The con tact member hasprovision for adjustment into various posit-ions across the width of theweb, to detect an excessive or subnormal moisture content in a portionof the web, v

caused by improper crown conditions in any of the rolls, non-uniformpressures or unequal weighting of the presses, or a dirty streak in thefelt. l

In applying the invention to the manufacture of paper on a paper makingmachine, a moisture indicating or indicating and recording mechanism ispreferably installed after each point lat which a change in moisturecontent occurs, for example, between the couch rolls and the rst press,between successive presses, and at the entrance to the dryers. Thecondittion of the web of stock after passing each operation andparticularly its progressive changes in moisture content in passingthrough the machine site.y adjustments to be m/ade to secure ef ficientoperation of the mechanisms operating on the stock but also enables theoperator to determine when a felt or jacket has become worn out andshould be replaced and thus avoids the premature removal of a felt orjacket or the continu-ed use of a felt or jacket after it has ceased tooperate efiiciently. This contributes to the efficient operation of themachine and reduces the cost of production.

l The invention has been illustrated in and will be readily understoodfrom the accompanying drawings in which Fig. 1 illustratesdiagrammatically the application of the invention to a Fourdrinier paperma-y chine; Fig. 2 is a perspective detail view illustrating thepreferred form of the moisture measuring mechanism; Fig. 3 is a sideIelevation of the measuring device shown in Fig. 2; and Fig. 4 is asection on line 4 4 of Fig. 3.

In Fig-1 the,v paperstock'which is indlcated. at S' coming 'from theFourdrinier wire and the couch rolls passes onto the felt 6 by which'itis carried between the upper and lo-wer press rolls 8 and 10 of thefirst press, where a partof the moisture is removed from the stock bypressure applied to the top roll. This pressure may be regulated by theusual means not indicated. The felt is carried on the usual supportingand tension rolls illustrated in Fig. 1. The web of stock from whichpart of the moisture has been removed by the press rolls and felts ofthe first press passes therefrom lonto the felt 12 to be carried betweenthe upper and lower press rolls14 and 16 of a second press, whereadditional moisture is expressed from the web in the same manner. Fromthis second press the web passes over a guide roll 18 to a dryer whichis indicated generally 'at 20 the web initially passing over the firstdryer of' the dryer stack, which is commonly knownas the baby dryer andindicated in Fig. 1 at 22.

In passing through the machine the web of paper stock is subjected tosuccessive operations, each of which removes a part of the moisture inthe stock and changes its condition. Means is provided for indicatingthe moisture of the stock between successive operations thereon', sothateach of the mechanisms operating on vthe web may be so regulated thatuniform and efficient operation is insured. As illustrated in thedrawings,

the moisture indicating and 'recording mechanism isarranged/toengagewiththc web 'afterjit v leaves-tliefirstpress roll'and alsov`while is-passi-n cv'er''therbaby dryer.

Als'ora slmilargme'c anism'jmay, if desired, be applied tothe.v web-pvas 'lcavesthe couch Each',moisture'in'dicating mechanism 'com--Pressa-'Pw fsf. slssfflvtlsirhivh' i the i1. lustrated -emb0dimenterf/'the 'invention are tuting one electrode which engages over a largesurface contact with the web of paper stock. The contact on the oppositeside of the sheet comprises a phosphor bronze sheet 24, preferably about.O05 of' an inch in thickness, the upper end of which is connected to afibre sleeve 26 sli'dingly received upon a fibre supporting bar 28arrangedl directly above the baby dryer. Provision is made forconduction of electrical currents to the electrode 24 through a brasstube 30 received within the fibre tube 28, the latter being slotted at82 to receive a contact spring 34 which connects between the yelectrode24 and the brass tube 80. The fibre and brass tubes constituting asupporting bar may be received iny suitable brackets on the sides of themachine and an electrical connection made directly to the brass tube 80.The electrode 24 has a series of slits at its lower end to provide aseries of fingers 36 which rest upon and insure electrical contact witha large surface of the web of paper stock. The fingers areV curled orbent over at the lower ends, the curled portions being filled withsolder, as indicated at 38, to lend weight to the phosphor bronze sheet,which, being flexible, readily conforms to the shape of the roll. Thistype of electrode not only gives a contact of large area, but alsopossesses the advantage of not being subject to disturbance or irregularoperation by reason of inequality or roughness in the paper stock, thefingers 36 closely conforming to the web regardless of thecharacteristics of the latter. Moreover, the ngers are selfcleaning to alage extent, the movement of the web directly under them serving toprevent accumulation of any fibrous material thereupon. The sleeve 26upon which the electrode is mounted may be moved transversely to anyposition on the supporting bar. This is most conveniently accomplishedby an operative through the use of a pole engaging one side or the otherof the sleeve 26. Variations in moisture content transversely ofthe/sheet may thus be measured, in order to detect faults due toimproper crowning, dirty or worn felts, or im-4 strument inasmuch as theroll 22 may be used as a lower electrode, it being' necessary merely toapply the electrode 24 to the opposite surface of the web. The moisturecontent of the web between the first .and

second presses may also be indicated by a second pair of electrodesconsisting of a metal roll 40 over which the web passes anda phosphorbronze electrode 42 contacting with the opposite side of the web and ofexactly similar construction tothe electrode 24. This measuring deviceis arranged to engage with the web directly after the latter passesthrough the press rolls 8 and 10. A similar arrangement may be appliedto indicate the moisture content of the web immediately after its pasagefrom the couch rolls, not shown in the figure.

The electrical connections for measuring the moisture content aredescribed as fol-I lows: Associated with each pair ofelectrodes is aregistering meter indicated at 44 and 46 respectively, although onemeter ymay be used for both measuring circuits in an obvious manner ifdesired. The meters 44 and 46 operate by measurement of the currentthrough the web of stock to indicate and record the electricalresistance offered by the web to the passage of current therethrough.The connections to the meter 44 only will be described, and it willbeunderstood that those to the meter 46'wi1l be identical therewith.Current comes from a 11G-volt alternating current line, one side ofWhich connects by a conductor 50 with the meter circuit and thence withthebrass sleeve 80, the other side of the line being grounded at 52. Thecircuit is completed through the roll 22 ofthe dryer, which being a partof the machine is at ground potential. The meter circuit includes avariable series resistance 54 and 'a shunt circuit including a variableresistance 56, a fixed resistance 57 and a relay 60, the contacts 62 ofwhich are in the series circuit of the meter. The shunt circuit servesto divide od a determinable portion of the current from the meter sothat the readings thereof may be properly controlled and kept withinproper limits. A resistance 64 of approximately 800 ohms is connectedbetween the ground connection and the electrode 24 so that it shuntstheweb of paper stock which is being measured, and

by carrying a portion of the current pro` fholds them open to protectthe meter from `fthe additional rush'of current.

v The relay, which may be. of any usual or preferred form 1s preferablyspring-controlled, so that upon normal operation by the insertion of aweb The meters are preferably of the record-v ing type, carryingsuitable charts which may be available for permanent record of thevariations in resistance of the web. From the measurement of knownsamples the relation between the moisture 'content of the web and itselectrical conductivityl may be determined so that the measurement 'ofresistance in the meter may be used to determine the moisture contentupon reference to the predetermined statistics.

Inasmuch as it is desirable that the meter should give a trueindicationof the moisture content`of the web, regardless of theelectrical conductivity of the water which is being used, it isnecessary to compensate for any changes in conductivity due to changesin the salt content or concentration in the water. For this purpose acalibrating ele.- ment indicated at 1s provided. This element comprisestwo electrodes 72 and 74 which are adapted to be connected into thecircuit in place of the web of paper stock passing between theelectrodes 22 and 24.v A double-throw switch 76 serves toconnect eitherthe web of paper or the calibrating element in circuit. A similar switch78 associated with the meter 46 permits this meter .also to be connectedwith the Calibrating -mined by. the conductivity of the water whichcirculates through the Calibrating cell. It will be seen that inasmuchas this water is expressed from the stock the use of the Calibratingelement determines the operation of the meter for the particular waterwhich is being used. The meter may now be adjusted so that it comes to aknown reading which may have been predetermined from measurements undernormal conditions of operation. When the switch 76 is thrown to itsleft-hand position so as to include the web vof paper stock in thecircuit, the variations of conductivity of the water will have beenc-ompensated for so that the meter will give a true indication of thepercentage of moisture in the paper stock.

What is claimed is:

1. The method of manufacturing paper which consists in subjecting atraveling` web of paperv stock to succesive operations, passing acurrent of electricity through the web at'points in its travel betweenoperations thereon, indicating the resistance oeredby lll the web to thepassage of the current at said points, and regulating the operations tomaintain said resistance substantially constant.

2. The method of manufacturing paper which consists in vsubjecting atraveling web of paper stock to successive operations, passing anelectric current through the web at points in its travel betweenoperations thereon, measuring the resistance ofl'ered by the web to thepassage of the current .at each of said points, and regulating theoperations to vary the resistance readings and consequently the moisturecontent progressively in passing through successive operations.

3. In a paper making machine, the combination with the mechanisms forforming and operating on the web of paper stock, of means for measuringthe moisture in the web at a point in its travel through the machinecomprising electrodes at opposite sides of and supported by the web, ameter for indicating the resistance offered by the stock to the passageof a current between the electrodes, and means for laterally adjustingthe measuring means from one side of the machine to the other.

4L.. in a paper making machine, the combination with the mechanisms forforming and operating on the web of paper stock, of means for measuringthe moisture in the web comprising an electrode contacting with the.web, means cooperating with the electrode to permit passage of anelectric current through the web from one side to the other, a meter forindicating the resistance offered to the passage of current through theweb, and means permitting lateral adjustment of the electrode betweenthe sides of the machine.

5. ln a paper making machine, the combination with the mechanisms forforming and operating on the web of paper stock, of means for measuringthe moisture in the web comprising a roll over which the web passes anda contact member engaging the opposite side of the web, an electricalcircuit including the roll and the web for causing passage of a currentthrough the web, a meter for indicating the resistance offered by thestock to the passage of the current therethrouglnand a support on whichthe Contact member is slidingly received above the web to permit lateraladjustment for measurement of moisture content at different parts oftheweb. v

6. In a paper making machine, the combination with the-mechanisms forforming and operating on'the vweb-of paper stock7 of means for measuringthe moisture in the web comprising a roll over which the web passes anda contact member engaging with the opposite side of the web andcomprising a thin flexible sheet of conducting material supported abovethe web and adapted to conform thereto' for a substantial portion'v ofits length, and a meter for indicating the resistance offered by thestock to the passage of the current therethrough from between the rolland the contact member.

'i'. In a paper making machine, the combination with the mechanisms forforming and operating on the web of paper stock,

of a roll over which the web passes, an electrode contacting with theopposite side of the web from the roll and comprising a thm flexiblesheet of conducting material supported at one end above the roll andweighted at the other end to cause it to v conform to the web over asubstantial sura roll overv which the web passes, an elec-y trodesupport above the web, a contact electrode mounted on the electrodesupport and comprising a thin flexible sheet of conducting materialextending from the support directly to the web and arranged to conformto the latter for a substantial length, the contact electrode beingadjustable on a support transversely of the machine, means for passingan electric current between the roll and the electrode, and means' formeasuring the resistance oered to the passage of current.

9. In a paper making machine, the combination with the mechanisms forforming and operating on the web of paperV stock, of means for measuringthe moisture in the web comprising a roll over which the web passes anda plurality of weighted Hexible contact fingers engaging with andconforming to the roll for a substantial length, means for passing anelectric current between the roll and the electrode, and means formeasuring the resistance-oered to the passage of current.

10. In a paper making machine, the combination with the 'mechanisms forforming and operating on the web of paper stock, of means for measuringthe moisture in the web including means for passing an electric currentthrough the web at a point in its travel, a meter for measuring theresistance offered by the web to the passage of the current, Calibratingmeans responsive to variations in the conductivity' of the water used inthe manufacture of the paper, and means for connecting the Calibratingmeanswith the. meter to permit. adjustment. of thelatter to compensate"for changes in the. conductivity o the water. i

1l. In a papermaking machine, the com bination with the mechanisms forforming and operating on the web o f paper stock,

of means for measuring the electrical conductivity of the web at a pointin its travel to determine the moisture content of the web, aCalibra-ting device comprising electrodesl immersed in Water of the'sameconductivity as that used in the manufacture of the paper, and means forconnecting the means to {permit adjustment of the latter to compensatefor variations in the conduc-'.l0

tivty of the Water.

EZEKIEL J. WILSON. EDWIN A. REES.

